Best Exchange Rate APIs in 2026 — Honest Comparison
A no-nonsense roundup of the best exchange rate APIs in 2026: AllRatesToday, Fixer, Open Exchange Rates, ExchangeRate-API, XE, and Frankfurter — with honest pros and cons.
There are dozens of exchange rate APIs. Most look identical until you actually try to ship with them — then the rough edges show up: HTTP-only free tiers, hourly updates dressed up as "real-time", base-currency lock-in, or an annual contract you didn't sign up to negotiate. This roundup covers the six providers we see most often, with honest trade-offs.
Disclosure: AllRatesToday publishes this guide. Pricing and feature details are taken from each provider's public website at time of writing. We've tried to keep the comparisons fair — verify current details on the vendor's own site before deciding.
Quick comparison
| Provider | Free tier | Updates | Best for |
|---|---|---|---|
| AllRatesToday | 300/mo, HTTPS, real-time | Real-time per request | Devs and SaaS who want fresh data + EUR pricing |
| Fixer.io | 100/mo, HTTP-only on free | Hourly on lower tiers | Teams already on the apilayer ecosystem |
| Open Exchange Rates | 1,000/mo, USD base only | Hourly | Devs who need a higher free quota |
| ExchangeRate-API | ~1,500/mo | Daily | Static dashboards, low-frequency reports |
| XE Currency Data API | 10-day eval only | Real-time | Banks, large fintechs, OFX brokers |
| Frankfurter | Unlimited (open source) | Daily (ECB reference) | Hobby projects, internal tools |
1. AllRatesToday
Best for: developers and SaaS teams who want fresh mid-market rates without enterprise pricing.
Pros
- Real-time per-request quotes
- HTTPS on the free tier
- Official SDKs for JS, Python, PHP, React
- EUR pricing from €4.99
Cons
- Free tier is smaller (300 req/mo)
- No precious metals or crypto in core API
2. Fixer.io
Best for: teams already on the apilayer marketplace who want a familiar setup.
Pros
- Long-running, well-known brand
- Wide currency coverage
Cons
- HTTP-only on the free plan
- Hourly updates on lower tiers
- Pricing jumps quickly between tiers
If those cons matter, see the Fixer alternative comparison.
3. Open Exchange Rates
Best for: teams who need a generous free quota and don't mind hourly updates.
Pros
- 1,000 req/mo on free
- Mature, battle-tested
Cons
- Free tier locks you to USD base
- Updates hourly, not real-time
- Historical data is paid-only
See our OXR comparison.
4. ExchangeRate-API
Best for: dashboards and reports that only need a daily snapshot.
Pros
- High free quota
- Simple JSON
Cons
- Daily updates only on free
- SDKs are community-maintained
5. XE Currency Data API
Best for: banks and large fintechs that need a recognised enterprise vendor.
Pros
- Trusted brand, deep coverage
- Precious metals and crypto available
Cons
- No self-serve plans
- Annual enterprise contracts
- Quote-based pricing
6. Frankfurter
Best for: hobby and internal projects that can live with ECB reference rates.
Pros
- Free and open source
- No API key needed
Cons
- Daily ECB rates only — not real-time
- No SLA, no support
- Limited currency coverage
How to pick
- Need fresh rates and a developer-friendly buying experience? AllRatesToday.
- Need a recognised enterprise vendor with annual contracts? XE.
- Just exploring? Frankfurter for daily ECB rates, AllRatesToday for real-time.